The rectangle is divided into four parts C, D, E and F. The ratio of Part C to Part D is 7 : 3 and the ratio of Part D to Part E is 3 : 2.
- Find the ratio of Part C to Part D to Part E.
- Given that Part F is 72 m2 , find the area of the rectangle.
(a)
| C |
D |
E |
F |
| 7x1 |
3x1 |
|
|
| |
3x1 |
2x1 |
|
| 7 u |
3 u |
2 u |
72 m2 |
Part D is the repeated identity.
LCM of 3 and 3 = 3
Part C : Part D : Part E = 7 : 3 : 2
(b)
Part C + Part D = Half of the rectangle
Part E + Part F = Half of the rectangle
Part C + Part D and Part E + Part F are equal.
Part C + Part D = Part E + Part F
7 u + 3 u = 2 u + 72
7 u + 3 u - 2 u = 72
8 u = 72
1 u = 72 ÷ 8 = 9
Area of the rectangle
= 2 x (2 u + 72)
= 2 x (2 x 9 + 72)
= 2 x (18 + 72)
= 2 x 90
= 180 m
2 Answer(s): (a) 7 : 3 : 2; (b) 180 m
2 
